#include <stdio.h>
#include <signal.h>
#include <unistd.h>
volatile int  value = 0;
void handle(int signo)
{
    printf("value from 0 to 1\n");
    value=1;
}

int main()
{
    signal(2,handle);  
    printf("pid:%d\n",getpid());
    while(!value);


    return 0;
}